The long pentraxin PTX-3 in prevalent hemodialysis patients: associations with comorbidities and mortality

Pentraxin 3 is a Novel Inflammatory Marker of HLA-B27-associated Uveitis

PURPOSE

Evidence exists that pentraxin 3 (PTX3) is involved in the pathogenesis of autoimmune diseases. The aim of this study was to analyze the levels of PTX3 in aqueous humor (AH) samples from patients with specific autoimmune uveitic entities. In addition, we correlated PTX3 levels with the levels of proinflammatory cytokines and chemokines and the clinical disease activity.

METHODS

AH samples from patients with active uveitis associated with human leukocyte antigen (HLA)-B27-related inflammation (n = 12), Behçet's disease (BD) (n = 13), Vogt-Koyanagi-Harada (VKH) disease (n = 12), sarcoidosis (n = 8) and control subjects (n = 9) were measured with the use of multiplex assays.

RESULTS

When considering all uveitis patients as one group (n = 45), PTX3 levels were significantly increased compared to controls (p = 0.002). When comparing the four individual disease groups to controls, PTX3 levels were significantly higher in only HLA-B27-associated uveitis (p < 0.001). PTX3 levels were significantly higher in patients with HLA-B27-associated uveitis than in patients with BD (p = 0.034) and VKH disease (p < 0.001). PTX3 levels had a significant correlation with clinical disease activity (r = 0.480; p = 0.001) and strong positive correlations with aqueous humor levels of interferon-γ (r = 0.749; p < 0.001), interleukin (IL)-1ß (r = 0.804; p < 0.001), IL-6 (r = 707; p < 0.001), CCL20 (r = 0.691; p < 0.001) and CXCL8 (r = 0.775; p < 0.001).

CONCLUSIONS

PTX3 is an inflammatory marker and might exert a pathogenic role in HLA-B27-associated uveitis.

Pentraxin-3 and Outcomes in CKD: A Systematic Review and Meta-analysis

Rationale & Objective

Long pentraxin-3 (PTX-3) serves as a biomarker for prognosticating adverse clinical outcomes in individuals with chronic kidney disease (CKD). The objective of the current meta-analysis was to evaluate the prognostic efficacy of PTX-3 in patients with CKD. In addition, we compared the prognostic effectiveness of PTX-3 and the short pentraxin C-reactive protein (CRP) in the identical cohort of patients with CKD.

Study Design

A systematic review and meta-analysis.

Setting & Participants

Patients with CKD treated with or without dialysis.

Selection Criteria for Studies

A cohort study with a minimum 1-year follow-up.

Data Extraction

Risk measurements, adjusted hazard risk with 95% CI, and modified variables.

Analytical Approach

To aggregate the adjusted effect estimates, a fixed-effects or random-effects model was employed.

Results

Nine studies covering 1,825 patients with CKD were selected in the present review. Six of the 9 studies exclusively included patients receiving hemodialysis. The collected findings indicated that patients with CKD in the highest tertile of PTX-3 demonstrated significantly higher risks of all-cause mortality (HR, 1.92; 95% CI, 1.44-2.56), cardiovascular death (HR, 1.98; 95% CI, 1.28-3.05), infectious death (HR, 5.26; 95% CI, 1.60-17.31), and fatal and nonfatal cardiovascular events (HR, 1.81; 95% CI, 1.35-2.42), as compared with those in the lowest tertile. These significant associations with risk were also observed when effect estimates were presented as per unit change in the PTX-3. Moreover, when comparing the prognostic value of PTX-3 and CRP in the same individuals (5 studies covering 904 patients), PTX-3 proved to be a satisfactory predictor of adverse events in these patients, whereas CRP failed to exhibit such predictive capability, regardless of the type of effect estimate used.

Limitations

A relatively small sample size and some heterogeneity.

Conclusions

Pentraxin 3 is associated with adverse events in individuals with CKD and may be a more reliable predictor of adverse clinical events than CRP in this population.

Pentraxin 3 plays a key role in tubular cell senescence and renal fibrosis through inducing β-catenin signaling

Renal fibrosis is the common pathological feature of various chronic kidney diseases (CKD). Tubular cell senescence plays a key role in the progression of renal fibrosis. However, the underlying mechanisms are still in mystery. In this study, we identified, Pentraxin 3 (PTX3), belonging to the Pentraxin family, is a new fibrogenic factor. PTX3 was increased in various CKD models. PTX3 was primarily localized in tubular epithelial cells and upregulated, accompanied by mitochondrial dysfunction and cellular senescence. Overexpression of PTX3 aggravated mitochondrial damage and accelerated cell senescence in tubular cells, leading to more severe fibrogenesis in kidneys. However, knockout of PTX3 significantly preserved mitochondrial homeostasis, and blocked cellular senescence in primary cultured tubular cells. Furthermore, KYA1797K, a destabilizer of β-catenin, greatly inhibited PTX3-induced mitochondrial dysfunction, tubular cell senescence, and renal fibrosis. Overexpression of PTX3 triggered nuclear translocation of β-catenin, an activating form of β-catenin. PTX3-induced mitochondrial dysfunction and tubular cell senescence were also significantly inhibited by knockdown of p16INK4A, a senescence-related protein. In a clinical cohort, we found PTX3 was increased in urine and serum in patients with CKD. Urinary PTX3 negatively correlated with eGFR. PTX3 also increased gradually following the severity of diseases, triggering the fibrogenesis. Taken together, our results provide strong evidences that PTX3 is a new fibrogenic factor in the development of renal fibrosis through β-catenin-induced mitochondrial dysfunction and cell senescence. This study further suggests PTX3 is a new diagnostic factor to renal fibrosis and provides a new therapeutic target against renal fibrosis.

Long Pentraxin 3 as a Broader Biomarker for Multiple Risk Factors in End-Stage Renal Disease: Association with All-Cause Mortality

Persistent inflammation in end-stage renal disease (ESRD) patients is known to underlie the progression of chronic kidney disease and to be associated with multiple risk factors including malnutrition, atherosclerosis, and cardiovascular disease (CVD). The acute-phase protein pentraxin 3 (PTX3) has a proven potential as a local inflammatory biomarker, but its clinical utility in ESRD remains unclear. Circulating levels of PTX3 and classical inflammatory mediators, including the clinical prototypical C-reactive protein (CRP), were assessed in 246 ESRD patients on dialysis and analysed in relation to the lipid profile, adipokine levels, and nutritional, cardiac, and renal fibrosis markers. Occurrence of deaths was recorded for the following year. Contrarily to the classical inflammatory markers, PTX3 levels were negatively correlated with nutritional markers and associated with a less atherogenic lipid profile. Levels of the cardiac and renal fibrosis markers and of the oxidized LDL/LDL-C ratio were found to be independent determinants of PTX3 concentration. When comparing inflammatory mediators, the increase in the PTX3 levels was the only predictor of all-cause mortality in dialysis patients in a survival model adjusted to all markers under study, other than the inflammatory ones, besides common confounding factors in dialysis. Data support the clinical applicability of PTX3 as a broader inflammatory biomarker than the classical ones, presenting a close association with inflammation, malnutrition, CVD, and renal fibrosis and a great potential to predict all-cause mortality in dialysis patients. The pleiotropic character of PTX3 may be of clinical relevance, and it could be targeted to ameliorate the high morbidity and mortality associated with ESRD.

PTX3, a Humoral Pattern Recognition Molecule, in Innate Immunity, Tissue Repair, and Cancer

Innate immunity includes a cellular and a humoral arm. PTX3 is a fluid-phase pattern recognition molecule conserved in evolution which acts as a key component of humoral innate immunity in infections of fungal, bacterial, and viral origin. PTX3 binds conserved microbial structures and self-components under conditions of inflammation and activates effector functions (complement, phagocytosis). Moreover, it has a complex regulatory role in inflammation, such as ischemia/reperfusion injury and cancer-related inflammation, as well as in extracellular matrix organization and remodeling, with profound implications in physiology and pathology. Finally, PTX3 acts as an extrinsic oncosuppressor gene by taming tumor-promoting inflammation in murine and selected human tumors. Thus evidence suggests that PTX3 is a key homeostatic component at the crossroad of innate immunity, inflammation, tissue repair, and cancer. Dissecting the complexity of PTX3 pathophysiology and human genetics paves the way to diagnostic and therapeutic exploitation.

PTX3 in serum induces renal mesangial cell proliferation but has no effect on apoptosis

The present study aimed to investigate the effect of pentraxin 3 (PTX3) on the regulation of proliferation and apoptosis in human glomerular mesangial cells (HMCs). Small interfering (si)RNA was designed and synthesized to inhibit the expression of endogenous PTX3, and the effects on the proliferation and apoptosis of HMCs were detected by flow cytometry and an MTT assay. Western blot analysis was used to detect the activation of mitogen-activated protein kinase (MAPK) proteins in HMCs with PTX3 knockdown. Three siRNAs targeting PTX3 were individually transfected into HMCs for 48 h, and reverse-transcription quantitative PCR demonstrated that the relative mRNA expression of PTX3 was significantly decreased in all groups by up to 79.62% of that in the control group (P<0.05). Following transfection with PTX3-siRNA, the viability of an HMC line was significantly decreased in comparison with that of a control group transfected with scrambled siRNA. However, PTX3-siRNA did not significantly effect early and late apoptotic cell populations in HMCs compared with those in the control. Endogenous PTX3 interference was found to significantly decrease p38 MAPK, extracellular signal-regulated kinase 1/2 and c-Jun N-terminal kinase phosphorylation. In conclusion, silencing of PTX3, inhibited the proliferation of HMCs via MAPK pathways, but exerted no effect on the apoptosis of HMCs.

Biochemical and Clinical Impact of Organic Uremic Retention Solutes: A Comprehensive Update

In this narrative review, the biological/biochemical impact (toxicity) of a large array of known individual uremic retention solutes and groups of solutes is summarized. We classified these compounds along their physico-chemical characteristics as small water-soluble compounds or groups, protein bound compounds and middle molecules. All but one solute (glomerulopressin) affected at least one mechanism with the potential to contribute to the uremic syndrome. In general, several mechanisms were influenced for each individual solute or group of solutes, with some impacting up to 7 different biological systems of the 11 considered. The inflammatory, cardio-vascular and fibrogenic systems were those most frequently affected and they are one by one major actors in the high morbidity and mortality of CKD but also the mechanisms that have most frequently been studied. A scoring system was built with the intention to classify the reviewed compounds according to the experimental evidence of their toxicity (number of systems affected) and overall experimental and clinical evidence. Among the highest globally scoring solutes were 3 small water-soluble compounds [asymmetric dimethylarginine (ADMA); trimethylamine-N-oxide (TMAO); uric acid], 6 protein bound compounds or groups of protein bound compounds [advanced glycation end products (AGEs); p-cresyl sulfate; indoxyl sulfate; indole acetic acid; the kynurenines; phenyl acetic acid;] and 3 middle molecules [β₂-microglobulin; ghrelin; parathyroid hormone). In general, more experimental data were provided for the protein bound molecules but for almost half of them clinical evidence was missing in spite of robust experimental data. The picture emanating is one of a complex disorder, where multiple factors contribute to a multisystem complication profile, so that it seems of not much use to pursue a decrease of concentration of a single compound.

Pentraxins in the activation and regulation of innate immunity

Humoral fluid phase pattern recognition molecules (PRMs) are a key component of the activation and regulation of innate immunity. Humoral PRMs are diverse. We focused on the long pentraxin PTX3 as a paradigmatic example of fluid phase PRMs. PTX3 acts as a functional ancestor of antibodies and plays a non-redundant role in resistance against selected microbes in mouse and man and in the regulation of inflammation. This molecule interacts with complement components, thus modulating complement activation. In particular, PTX3 regulates complement-driven macrophage-mediated tumor progression, acting as an extrinsic oncosuppressor in preclinical models and selected human tumors. Evidence collected over the years suggests that PTX3 is a biomarker and potential therapeutic agent in humans, and pave the way to translation of this molecule into the clinic.

Association of genetic variants of pentraxin 3 rs3816527 with hypertension in Chronic kidney disease patients

Hypertension is a nearly constant feature and both a cause and a consequence of chronic kidney disease (CKD). Atherosclerotic lesions showed a marked expression of pentraxin 3 on the surface of lumen and in the plaque. The aim was to assess the correlation of exon 2 of pentraxin 3 gene SNP rs3816527 with hypertension with CKD. The study was conducted on 110 CKD patients (60 patients with and 50 patients without hypertension) and 40 healthy subjects as control. Laboratory investigations including the measurement of fasting blood glucose, lipid profile, and indices of oxidative stress, liver function tests, and renal function tests were done. Genotyping of pentraxin 3 gene SNP rs3816527 was done by real-time PCR. There was a significant difference between CKD patients with hypertension and the subjects in the control group regarding systolic and diastolic BP, urea, creatinine, GFR, TG, cholesterol, LDL, HDL, and total antioxidant levels (p < 0.001). There is a statistically significant difference between CKD patients with hypertension and the other studied groups regarding the frequencies of AA genotype and A allele of exon 2 SNP of pentraxin 3 gene compared to CC genotype and C allele (wild type) (p < 0.001), while there was significant difference between CKD patients without hypertension and control (p > 0.05). Pentraxin 3 AA genotype SNP rs3816527 can be considered as a potential biomarker and a risk factor for CKD patients, especially hypertensive patients, and specifically as an independent predictor of hypertension in CKD.

The inflammatory protein Pentraxin 3 in cardiovascular disease

The acute phase protein Pentraxin 3 (PTX3) plays a non-redundant role as a soluble pattern recognition receptor for selected pathogens and it represents a rapid biomarker for primary local activation of innate immunity and inflammation. Recent evidence indicates that PTX3 exerts an important role in modulating the cardiovascular system in humans and experimental models. In particular, there are conflicting points concerning the effects of PTX3 in cardiovascular diseases (CVD) since several observations indicate a cardiovascular protective effect of PTX3 while others speculate that the increased plasma levels of PTX3 in subjects with CVD correlate with disease severity and with poor prognosis in elderly patients.

In the present review, we discuss the multifaceted effects of PTX3 on the cardiovascular system focusing on its involvement in atherosclerosis, endothelial function, hypertension, myocardial infarction and angiogenesis. This may help to explain how the specific modulation of PTX3 such as the use of different dosing, time, and target organs could help to contain different vascular diseases. These opposite actions of PTX3 will be emphasized concerning the modulation of cardiovascular system where potential therapeutic implications of PTX3 in humans are discussed.

Impact of chronic kidney disease stages on atherosclerotic plaque components on optical coherence tomography in patients with coronary artery disease

The progression of coronary atherosclerosis has been influenced by the presence of chronic kidney disease (CKD). This study investigated the impact of CKD stages on coronary plaque components observed on optical coherence tomography (OCT). We investigated 296 native coronary lesions with stable angina pectoris treated with stent implantation. All lesions were divided into the three groups according to the values of estimated glomerular filtration rate (eGFR, mL min^-1 1.73 m^-2): the non-CKD group (eGFR ≥60, n = 142), CKD group (15 ≤ eGFR < 60, n = 126), and end-stage kidney disease (ESKD) group (eGFR <15 and/or hemodialysis, n = 28). Among the groups, plaque morphologies at the narrowest culprit sites on OCT were evaluated. The CKD group had a larger lipid arc [207.5 (88.3-264.5) vs. 159.3 (73.3-227.7) degrees, P = 0.037] and longer lipid length [2.4 (0.0-5.7) vs. 0.0 (0.0-4.7) mm, P = 0.017] than the non-CKD group. The ESKD group had a thinner fibrous cap [120 (70-258) vs. 170 (100-270) μm, P = 0.044], higher prevalence of plaque rupture (28.6 vs. 12.3 %, P = 0.038), and larger calcification arc [124.8 (0.0-194.3) vs. 0.0 (0.0-125.4) degrees, P = 0.025] than the non-ESKD group (CKD + non-CKD groups). The presence of CKD was related to the growth of lipidic plaques. Furthermore, the advancement in the CKD stage to ESKD affected the occurrence of plaque rupture or progression of calcification.

Association between levels of pentraxin 3 and incidence of chronic kidney disease in the elderly

OBJECTIVE

Higher levels of the novel inflammatory marker pentraxin 3 (PTX3) predict cardiovascular mortality in patients with chronic kidney disease (CKD). Yet, whether PTX3 predicts worsening of kidney function has been less well studied. We therefore investigated the associations between PTX3 levels, kidney disease measures and CKD incidence.

METHODS

Cross-sectional associations between serum PTX3 levels, urinary albumin/creatinine ratio (ACR) and cystatin C-estimated glomerular filtration rate (GFR) were assessed in two independent community-based cohorts of elderly subjects: the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS, n = 768, 51% women, mean age 75 years) and the Uppsala Longitudinal Study of Adult Men (ULSAM, n = 651, mean age 77 years). The longitudinal association between PTX3 level at baseline and incident CKD (GFR <60 mL(-1) min(-1) 1.73 m(-2) was also analysed (number of events/number at risk: PIVUS 229/746, ULSAM 206/315).

RESULTS

PTX3 levels were inversely associated with GFR [PIVUS: B-coefficient per 1 SD increase -0.16, 95% confidence interval (CI) -0.23 to -0.10, P < 0.001; ULSAM: B-coefficient per 1 SD increase -0.09, 95% CI -0.16 to -0.01, P < 0.05], but not ACR, after adjusting for age, gender, C-reactive protein and prevalent cardiovascular disease in cross-sectional analyses. In longitudinal analyses, PTX3 levels predicted incident CKD after 5 years in both cohorts [PIVUS: multivariable odds ratio (OR) 1.21, 95% CI 1.01-1.45, P < 0.05; ULSAM: multivariable OR 1.37, 95% CI 1.07-1.77, P < 0.05].

CONCLUSIONS

Higher PTX3 levels are associated with lower GFR and independently predict incident CKD in elderly men and women. Our data confirm and extend previous evidence suggesting that inflammatory processes are activated in the early stages of CKD and drive impairment of kidney function. Circulating PTX3 appears to be a promising biomarker of kidney disease.

C-reactive Protein: Repeated Measurements will Improve Dialysis Patient Care

Systemic inflammation is a common feature in the uremic phenotype and associates with poor outcomes. The awareness regarding the importance of inflammation assessment in chronic kidney disease (CKD) patients has risen in recent years, and despite the development of novel biomarkers, C-reactive protein (CRP) is still the most measured inflammatory parameter. Notwithstanding, the possible weak points of CRP determination, this biomarker has demonstrated being useful both for guidance in clinical practice and for risk estimation. In addition, regular determination of CRP among dialysis patients has been associated with better outcomes in different dialysis facilities. Because persistent inflammation may be a silent reflection of various pathophysiologic alterations in CKD, it is crucial that inflammatory markers are regularly monitored and therapeutic attempts be made to target this inflammation.

Relationship of Neutrophil-to-Lymphocyte Ratio and Serum Albumin Levels with C-Reactive Protein in Hemodialysis Patients: Results from 2 International Cohort Studies

BACKGROUND/AIM

The neutrophil-to-lymphocyte ratio (NLR), defined as the neutrophil count divided by lymphocyte count, is an inexpensive and readily available parameter, which may serve as a surrogate for inflammation markers, such as C-reactive protein (CRP). The aim of this study was to determine the utility of NLR in the prediction of elevated CRP levels in hemodialysis (HD) patients.

METHODS

We analyzed 43,272 HD patients from 2 distinct cohorts within the Monitoring Dialysis Outcomes research collaboration in whom contemporaneous measurements of neutrophil and lymphocyte counts, serum albumin and CRP levels were available. Logistic regression was used to determine the relationship of trichotomized NLR (<2.5, 2.5-5 and >5.0) and albumin levels (<3.1, 3.1-4.0 and >4.0 g/dl) with elevated CRP levels (>10.0, >20.0 and >30.0 mg/l). Congruence of the prediction models was examined by comparing the regression parameters and by cross-validating each regression equation within the other cohort.

RESULTS

We found that NLR >5.0 vs. <2.5 (cohort 1: OR 2.3; p < 0.0001 and cohort 2: OR 2.0; p < 0.0001) was associated with CRP levels >10.0 mg/l. Stepwise increase in odds ratio for CRP >10.0 mg/l was observed with the combination of high NLR and low albumin levels (NLR >5.0 and albumin <3.1) (cohort 1: OR 7.6; p < 0.0001 and cohort 2: OR 11.9; p < 0.0001). Cross-validation of the 2 regression models revealed a predictive accuracy of 0.68 and 0.69 in the respective cohorts.

CONCLUSION

This study suggests that NLR could serve as a potential surrogate marker for CRP. Our results may add to diagnostic abilities in settings where CRP is not measured routinely in HD patients. NLR is easy to integrate into daily practice and may be used as a marker of systemic inflammation.

Relationships between plasma pentraxin 3 levels and inflammation markers patients with tunneled permanent catheter in hemodialysis

PURPOSE

Vascular access (VA) devices may contribute to chronic inflammation in hemodialysis (HD). Pentraxin 3 (PTX3) is a recently discovered acute phase protein that responds more rapidly than other inflammatory markers. This study compared PTX3 and other markers between HD patients and healthy controls.

METHODS

The study population included 30 patients with tunneled permanent catheter (TPC), 30 patients with arteriovenous fistula (AVF) and 30 healthy controls. Hemogram, biochemical assays, ferritin, high sensitive C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α) and PTX3 were evaluated in all groups.

RESULTS

PTX levels were highest in HD patients with TPC, intermediated in HD patients with AVF and lowest in healthy controls (5.2 + 2.4 vs. 3.1 + 1.3 vs. 1.8 + 0.7, p&lt;0.001 for all comparisons). PTX3 levels correlated strongly to hs-CRP (r = 0.857) and moderately to TNF-α, NLR, ferritin and total neutrophil count. PTX3 and albumin levels had a negative correlation. PTX3 levels were higher in patients with 8 months of TPC than those with 7 months or less.

CONCLUSIONS

PTX3 levels are significantly elevated in all patients on HD, but presence and extended duration of TPC are associated with incrementally higher levels of PTX3 and other inflammatory markers. PTX3 and NLR may be useful in assessing chronic inflammatory states in HD.

Correlation between arterial stiffness and inflammatory markers in autosomal dominant polycystic kidney disease patients with preserved renal function

AIM

To evaluate the association between arterial stiffness and inflammatory markers including C-reactive protein (CRP), pentraxin 3 (PTX3) and neutrophil-to-lymphocyte ratio (NLR) in autosomal dominant polycystic kidney disease (ADPKD) patients with preserved renal function.

METHODS

A total of 52 ADPKD patients [mean (SD) age 38.2 (12.8) years, 69.2 % were females] with preserved renal function and 25 healthy volunteers [mean (SD) age 35.5 (6.5) years, 48.0 % were females] were included. Data on patient characteristics, blood biochemistry, inflammatory markers [PTX3 (pg/mL), CRP (mg/dL) and NLR] and arterial stiffness [large artery elasticity index (LAEI) (mL/mmHg × 10) and small artery elasticity index (SAEI) (mL/mmHg × 100)] were recorded in patient and control groups. Correlation between inflammatory markers and arterial stiffness parameters was analysed in patients.

RESULTS

Overall, 42.3 % of ADPKD patients were hypertensive and 44.4 % were receiving renin-angiotensin-aldosterone system (RAAS) blockade therapy. Median levels for PTX3 [442.0 (20.0-4140.0) pg/mL vs. 220.5 (14.7-393.0) pg/mL, p < 0.001] and SAEI [4.90 (1.60-11.80) mL/mmHg × 100 vs. 6.45 (2.80-15.70) mL/mmHg × 10, p = 0.013] were significantly higher in ADPKD patients than in controls. PTX3 and CRP were not correlated with arterial elasticity, while NLR was significantly correlated with LAEI negatively (Rho = -0.278, p = 0.042).

CONCLUSION

In conclusion, our findings revealed increased PTX3 levels and reduced SAEI in patients as compared with controls, while no correlation between inflammatory markers studied and the small artery elasticity.

Plasma Pentraxin 3 Is Closely Associated with Peripheral Arterial Disease in Hemodialysis Patients and Predicts Clinical Outcome: A 6-Year Follow-Up

BACKGROUND

The aim of this study is to investigate the value of plasma PTX3 level for assessing peripheral artery disease (PAD) and clinical outcome in hemodialysis (HD) patients.

METHODS

The ankle-brachial index (ABI) was measured in HD patients. PTX3 levels in 116 HD patients were measured by ELISA.

RESULTS

Overall, 116 HD patients were enrolled; 21 (18%) patients had PAD. Using the ROC curve analysis for PAD, PTX3 (cut-off value 4.06 ng/ml, AUC 0.901, p < 0.0001) showed a significantly better positive predictive value than hsCRP (cut-off value 3.33 ng/ml, AUC 0.640, p < 0.05). During follow-up (mean 57 ± 26 months), 40 deaths (34%) occurred. Kaplan-Meier analysis found that those patients with elevated PTX3 had a significantly poor outcome (p < 0.0001), and Cox analysis further confirmed that PTX3 was an independent predictor of overall mortality (HR, 1.105, p = 0.03). For prediction of overall mortality, the AUC for PTX3 (cut-off value 3.22 ng/ml, AUC 0.690, p < 0.0001) was close to hsCRP (cut-off value 5.84 ng/ml, AUC 0.620, p < 0.001).

CONCLUSIONS

For the prediction of PAD in HD patients, the diagnostic sensitivity and specificity of PTX3 were higher than those of hsCRP. Furthermore, PTX3 was also a predictor of all-cause mortality in HD patients. PTX3 may be considered a novel biomarker of inflammation in HD patients.

Annual decline in pentraxin 3 is a risk of vascular access troubles in hemodialysis patients

Pentraxin 3 (PTX3), a multifunctional modulator of the innate immunoinflammatory response, is higher in patients undergoing hemodialysis than healthy control. Our study focused on annual change in PTX3 levels in patients with chronic hemodialysis, because regularly undergoing hemodialysis for many years modifies vascular inflammatory status. To demonstrate whether annual change in PTX3 is associated with vascular events, we measured blood levels of pentraxins (PTX3 and high-sensitivity C-reactive protein (hsCRP)) at baseline and in the next year in 76 hemodialysis patients and observed 20 patients with vascular access troubles during follow-up years. The annual decline in PTX3, but not hsCRP, is a significant risk of the incidence of vascular access trouble that is a critical and specific complication for hemodialysis patients (hazard ratio; 0.732 per +1 ng/mL/year in PTX3, (*) P = 0.039). This study is the first to focus on the annual change of pentraxins in a hemodialysis cohort.

Inflammatory biomarker pentraxin 3 (PTX3) in relation to obesity, body fat depots and weight loss

OBJECTIVE

The relation between inflammatory markers, adiposity and disease is under extensive study. Here we tested the hypothesis that the immunomodulatory protein pentraxin 3 (PTX3) is associated with adiposity in the general population.

METHODS

Serum PTX3 concentrations, body mass index (BMI), waist circumference (WC) and fat depots, as quantified by dual-energy X-ray absorptiometry and magnetic resonance imaging, were assessed in three community-based cohorts: ULSAM, n = 790, mean age 78 years; PIVUS, n = 1003, mean age 70 years, women 50%; and the NORDIET-trial, n = 86, mean age 53 years, women 63%. Participants were re-examined after 5 years (PIVUS, n = 804) or following a 6-week randomized controlled dietary intervention (NORDIET).

RESULTS

PTX3 levels were inversely associated with BMI and WC as well as with total and visceral fat (P < 0.05 for all; adjusted for age, inflammatory biomarkers and cardiovascular risk factors). The association between PTX3 and BMI appeared even stronger in nonobese individuals. A decrease in BMI over 5 years as well as weight loss following the NORDIET intervention were associated with increased serum PTX3 concentrations (P < 0.001).

CONCLUSIONS

These consistent data support an inverse association between circulating PTX3 and anthropometrical measures, calling for further mechanistic studies of the link between PTX3 and fat.

Design, synthesis and evaluation of novel diaryl pyrrolopyrimidine and pyrrolothiazine derivatives as inhibitors of tumor necrosis factor stimulated gene-14 (TSG-14) production

A novel series of pyrrolothiazines 2-4 and pyrrolopyrimidines 5-7 have been synthesized. The structures of these compounds were established by spectroscopic and element microanalytical data. The newly synthesized compounds were evaluated as inhibitors of TSG-14. The most effective results were obtained by the S-sec-butyl derivatives 6e (80%) and the N-ethyl derivatives 4e (70%).

The peptidic middle molecules: is molecular weight doing the trick?

Chronic kidney disease (CKD) is characterized by a gradual endogenous intoxication caused by the progressive accumulation of bioactive compounds that in normal conditions would be excreted and/or metabolized by the kidney. Uremic toxicity now is understood as one of the potential causes for the excess of cardiovascular disease and mortality observed in CKD. An important family of uremic toxins is that of the peptidic middle molecules, with a molecular weight ranging between 500 and 60,000 Da, which makes them, as a consequence, difficult to remove in the process of dialysis unless the dialyzer pore size is large enough. This review provides an overview of the main and best-characterized peptidic middle molecules and their role as potential culprits of the cardiometabolic complications inherent to CKD patients.

Obesity and high waist circumference are associated with low circulating pentraxin-3 in acute coronary syndrome

Background

Long pentraxin 3 (PTX3) is a component of the pentraxin superfamily and a potential marker of vascular damage and inflammation, associated with negative outcome in patients with acute coronary syndromes (ACS). Obesity is a risk factor for cardiovascular disease and PTX3 production is reported in abdominal adipose tissue. Low PTX3 is however reported in the obese population, and obesity per se may be associated with less negative ACS outcome.

Methods

We investigated the potential impact of obesity and high waist circumference (reflecting abdominal fat accumulation) on plasma PTX3 concentration in ACS patients (n = 72, 20 obese) compared to age-, sex- and BMI-matched non-ACS individuals.

Results

Both obese and non-obese ACS patients had higher PTX3 than matched non-ACS counterparts, but PTX3 was lower in obese than non-obese individuals in both groups (all P < 0.05). PTX3 was also lower in ACS subjects with high than in those with normal waist circumference (WC). Plasma PTX3 was accordingly associated negatively with BMI and WC, independently of age and plasma creatinine. No associations were observed between PTX3 and plasma insulin, glucose or the short pentraxin and validated inflammation marker C-reactive protein, that was higher in ACS than in non-ACS individuals independently of BMI or WC.

Conclusions

Obesity is associated with low circulating PTX3 in ACS. This association is also observed in the presence of abdominal fat accumulation as reflected by elevated waist circumference. Low PTX3 is a novel potential modulator of tissue damage and outcome in obese ACS patients.

Elevated circulating levels and tissue expression of pentraxin 3 in uremia: a reflection of endothelial dysfunction

Elevated systemic pentraxin 3 (PTX3) levels appear to be a powerful marker of inflammatory status and a superior outcome predictor in patients with chronic kidney disease (CKD). As previous data imply that PTX3 is involved in vascular pathology and that adipose tissue mass may influence circulating PTX3 levels, we aimed to study the importance of adipose tissue expression of PTX3 in the uremic milieu and its relation to endothelial dysfunction parameters. Plasma PTX3 and abdominal subcutaneous adipose tissue (SAT) PTX3 mRNA levels were quantified in 56 stage 5 CKD patients (median age 57 [range 25-75] years, 30 males) and 40 age and gender matched controls (median age 58 [range 20-79] years, 27 males). Associations between PTX3 measures and an extensive panel of clinical parameters, including surrogate markers of endothelial function, were assessed. Functional ex vivo studies on endothelial status and immunohistochemical staining for PTX3 were conducted in resistance subcutaneous arteries isolated from SAT. SAT PTX3 mRNA expression correlated with plasma PTX3 concentrations (rho = 0.54, p = 0.0001) and was increased (3.7 [0.4-70.3] vs. 1.2 [0.2-49.3] RQ, p = 0.02) in CKD patients with cardiovascular disease (CVD), but was not significantly different between patients and controls. The association to CVD was lost after adjustments. SAT PTX3 mRNA levels were independently correlated to asymmetric dimethylarginine and basal resistance artery tone developed after inhibition with nitric oxide synthase and cyclooxygenase (rho = -0.58, p = 0.002). Apparent positive PTX3 immunoreactivity was observed in both patient and control arteries. In conclusion, fat PTX3 mRNA levels are associated with measures of endothelial cell function in patients with CKD. PTX3 may be involved in adipose tissue-orchestrated mechanisms that are restricted to the uremic milieu and modify inflammation and vascular complications in CKD patients.

Plasma pentraxin 3 may be a better marker of peripheral artery disease in hemodialysis patients than C-reactive protein

Pentraxin 3 (PTX3) is a novel inflammatory cytokine produced in atherosclerotic plaque. We hypothesized that this marker may be a better predictor of peripheral artery disease (PAD) than C-reactive protein (CRP) in hemodialysis (HD) patients. The ankle–brachial index (ABI) was measured in HD patients. PTX3 levels in 116 HD patients and 30 healthy blood donors were measured by ELISA. A total of 116 HD patients (age: 56.44 ± 14.08 years) were enrolled; 21 (18%) patients had PAD. PTX3 was significantly higher in PAD versus non-PAD patients (5.55 ± 2.63 vs 2.32 ± 1.29 ng/mL; p < 0.001). In a univariate analysis, ABI correlated significantly with age, blood glucose and triglycerides, and plasma PTX3 ( r = -0.548, p < 0.001) and high-sensitivity (hs)CRP ( r = -0.495, p < 0.001). Using ROC curve analysis for PAD, PTX3 (cut-off value 4.06 ng/mL, AUC 0.901, p < 0.0001) showed a significantly better positive predictive value than hsCRP (cut-off value 3.33 mg/L, AUC 0.640, p < 0.05). Logistic regression analysis further confirmed that PTX3 (OR = 9.755, p = 0.001) was an independent predictor of PAD. In conclusion, we demonstrated that PTX3 may be a better marker of PAD than hsCRP, and independently correlated with PAD in HD patients.

Pentraxins in nephrology: C-reactive protein, serum amyloid P and pentraxin-3

Every clinician uses C-reactive protein (CRP) levels as a biomarker for systemic inflammation in acute disorders. Nephrologists also consider CRP levels as a predictor for overall mortality in patients with chronic kidney disease or end-stage renal disease. But what is the biological function of CRP? CRP is a member of the family of pentraxins, which are small pentameric innate immunity effector proteins. Pentraxins are absent or weakly expressed during homeostasis. However, the pro-inflammatory cytokines interleukin (IL)-1, IL-6 and tumour necrosis factor induce CRP and serum amyloid P (SAP) in hepatocytes, whereas the long pentraxins, such as pentraxin (PTX)-3, are produced in peripheral tissues and monocytic phagocytes. Pentraxins opsonize pathogens or other particles such as dead cells, for their phagocytic clearance or induce pathogen killing in extracellular compartments. In this review, we discuss the immunoregulatory properties of the different members of the pentraxin family. We discuss the evolving evidence demonstrating their roles in acute and chronic forms of kidney disease and the significance of SAP and PTX3 as additional biomarkers of innate immune activation and systemic inflammation.

Pentraxin 3, a sensitive early marker of hemodialysis-induced inflammation

BACKGROUND/AIMS

The purpose of this investigation was to determine if the long pentraxin 3 (PTX-3) may be a useful marker of intradialytic inflammation since it is rapidly released in the vasculature.

METHODS

PTX-3, interleukin-6, tumor necrosis factor-α and C-reactive protein were measured before and during a hemodialysis session in 22 patients and compared with healthy subjects. The effect of dialysis with low-flux, high-flux membranes and hemodiafiltration on the inflammatory response was compared in 11 patients.

RESULTS

C-reactive protein and interleukin-6 levels did not change, while a modest decrease in tumor necrosis factor-α was observed during hemodialysis. The plasma PTX-3 concentration was significantly increased (p < 0.001) after 60 min and peaked at 180 min during hemodialysis. There was no difference in the intradialytic increase in PTX-3 using different dialysis membranes and modalities.

CONCLUSION

PTX-3 stands out as a rapid and sensitive marker of hemodialysis-induced inflammation. Membrane flux and hemodiafiltration did not alter the inflammatory response.

Is Pentraxin-3 Stronger Than C-Reactive Protein to Determine Inflammation in Peritoneal Dialysis Patients?

Pentraxin-3 (PTX-3) is the prototype of long pentraxins and is produced by many tissues and organs including vascular endothelial cells in response to pro-inflammatory signals. It is thought to be an independent indicator of disease activity. We analyzed the correlation of PTX-3 with other markers of inflammation in peritoneal dialysis (PD) patients. Non-diabetic patients on chronic PD program who meet the dialysis adequacy criteria and who had no active infectious/inflammatory disease were included. Demographic and clinical parameters were recorded as well as hsCRP, fibrinogen, interleukin-6 (IL-6) and PTX-3 levels; and the correlation between them were studied. Twenty-five patients (mean age: 45.7±12.5 years; female/male ratio: 16/9) were included. Mean PTX-3 level was 2.16±2.76ng/ml. PTX-3 was found to be correlated positively with only IL-6 among inflammatory markers (r=0.827; p<0.001) but not with hsCRP. With linear regression model, IL-6 was the only independent determinant of PTX-3 levels. PTX-3 may be a more valuable marker of inflammation than CRP in patients on PD.

Exercise training in chronic kidney disease patients

Chronic kidney disease (CKD) is a major public health problem that affects an estimated 1.7 million Australians. Patients with CKD commonly progress to end-stage kidney disease (ESKD) requiring dialysis and/or kidney transplantation. They are at high risk of cardiovascular disease and many die from this prior to reaching ESKD. Few therapies are available to slow CKD progression and reduce cardiovascular morbidity and mortality. The benefit of exercise training has been well demonstrated in a range of disease conditions including ESKD and was recently highlighted by a systematic review in haemodialysis patients and a recent Cochrane review of all stages of CKD. However, the effects of exercise training in patients with CKD have not been extensively investigated. Our systematic search of the literature found only ten clinical trials in this area. The aim of this review is to review these studies, and to discuss the findings, safety considerations and suggest future areas of research. Overall, the majority of the studies are small, non-randomized, non-controlled trials. They have found that exercise training can increase exercise capacity, improve muscle strength and function, decrease blood pressure, and improve inflammation and oxidative stress biomarkers. The effects of exercise training on kidney function, cardiovascular disease and quality of life are unknown. Studies are needed to answer these questions and develop evidence-based exercise training guidelines for individuals with CKD.

Biomarkers of chronic inflammatory state in uremia and cardiovascular disease

Cardiovascular disease is the leading cause of death in the general population; traditional risk factors seem inadequate to explain completely the remarkable prevalence of cardiovascular mortality and morbidity observed in the uremic population. A role for chronic inflammation has been well established in the development of atherosclerotic disease, and, on the basis of these observations, atherosclerosis might be considered an inflammatory disease. Inflammation has been implicated in the etiology of coronary artery disease in the general population, and traditional inflammatory biomarkers such as C-reactive protein (CRP) and interleukin-6 (IL-6) have been shown to predict cardiovascular events in both symptomatic and asymptomatic individuals as well as those in the uremic population. Later on, new nontraditional markers were related to the risk of cardiovascular morbidity and mortality in general and in uremic population. As a consequence of the expanding research base and availability of assays, the number of inflammatory marker tests ordered by clinicians for cardiovascular disease (CVD) risk prediction has grown rapidly and several commercial assays have become available. So, up to now we can consider that several new nontraditional markers as CD40-CD40 ligand system and pentraxin-3 seem to be significant features of cardiovascular disease in general and in ESRD population.

Inverse relationship between the inflammatory marker pentraxin-3, fat body mass, and abdominal obesity in end-stage renal disease

BACKGROUND AND OBJECTIVES

Pentraxin-3 (PTX3) belongs to the same pentraxin superfamily of acute-phase reactants as C-reactive protein (CRP). Abdominal fat accumulation in ESRD is considered a chronic inflammatory state, but the relationship of PTX3 to this phenomenon is unknown. This study assesses plausible associations between PTX3 and surrogates of fat mass deposits in dialysis patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Circulating levels of PTX3, CRP, and IL-6 were cross-sectionally analyzed in relation to anthropometric and nutritional surrogate markers of fat tissue in two cohorts comprising 156 prevalent hemodialysis (HD) and 216 incident dialysis patients.

RESULTS

In both cohorts, PTX3 was negatively associated with body mass index (BMI) and fat body mass index (FBMI) derived from anthropometrics and leptin, whereas there was a positive association with adiponectin. In prevalent HD patients, those with larger waist circumference (above gender-specific median values) had lower PTX3, higher CRP, and higher IL-6 levels. This was also true in multivariate analyses. In both cohorts, multivariate regression analyses showed that PTX3 was negatively and CRP (or IL-6) was positively associated with FBMI.

CONCLUSIONS

Although CRP and IL-6 were directly associated with body fat, PTX3 levels showed negative correlations with surrogates of adipose tissue in two independent cohorts of ESRD patients. Understanding the underlying reasons behind these opposite associations may have clinical relevance given the survival advantage described for obese patients on dialysis.

The role of pentraxin-3 as a prognostic biomarker in paraquat poisoning

Paraquat poisoning has been a public health problem in both the developing and developed countries. Pentraxin 3 is a member of the pentraxin family which is expressed as part of the acute-phase response that begins after injury, trauma, and infection. The aim of our study is to determine whether PTX3 levels can be a significant marker of pulmonary fibrosis and outcome of survival in paraquat poisoning. To measure the plasma paraquat level, we collected serum of the patients immediately after admission. EDTA plasma samples for checking the plasma PTX3 concentration were taken before and after the 1st hemoperfusion and after the 2nd hemoperfusion therapy. PTX3 concentrations in EDTA plasma were determined using a commercial solid-phase enzyme-linked immunosorbent assay (ELISA). Plasma paraquat concentration was higher in survivors than in non-survivors (p<0.05). Maximal plasma PTX3 level was significantly higher in the pulmonary fibrosis group, and plasma PTX3 was significantly increased throughout hemoperfusion therapy (p<0.01). Moreover, increase in PTX3 was greater in non-survivors than survivors (p<0.05). Our results show that PTX3 is a useful biomarker of severity and outcome predictor in paraquat poisoning.

Risk factors for chronic kidney diseases may include periodontal diseases, as estimated by the correlations of plasma pentraxin-3 levels: a case-control study

BACKGROUND

Pentraxins are classical mediators of inflammation and markers of acute-phase reactions. Pentraxin-3 (PTX3) is believed to be a true independent indicator of disease activity. It has been associated with clinical outcomes in incident chronic kidney disease (CKD) and periodontal diseases. Periodontitis is lately being considered as a risk factor for CKD. However, no data are available on elevated PTX3 in patients with CKD associated with periodontitis.

METHOD

Sixty subjects were divided into three groups (n = 20) based on glomerular filtration rate (GFR) and periodontal parameters: healthy (group-1), CKD (group-2), and CKD with periodontitis (group-3). Plasma samples obtained from each patient were quantified for PTX3 using Enzyme-linked Immunosorbent Assay (ELISA).

RESULTS

Both patient groups with CKD had higher plasma PTX3 concentrations than control subjects. However, there was no significant difference between the two groups (groups 2 and 3). In all groups, plasma PTX3 correlated positively with periodontal parameters. Group 3 patients had higher concentrations of PTX3 (6.338 ng/ml) than group 2 (5.41 ng/ml) and group 1 (1.835 ng/ml).

CONCLUSIONS

Within the limits of the present study, the difference in plasma PTX3 levels between groups 2 and 3 was not found to be statistically significant (P > 0.05). However, as PTX3 values correlated positively with periodontal parameters, this model could contribute to identifying individuals with periodontitis at high risk of CKD. Thus, periodontal disease could serve as a risk factor for developing CKD. Further large-scale studies nullifying the confounders for CKD are warranted to confirm positive results.

Racial differences in the association of pentraxin-3 with kidney dysfunction: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Pentraxin-3 (PTX3), an inflammatory marker thought to be related to vascular inflammation, is elevated in advanced chronic kidney disease (CKD). Whether PTX3 is associated with mild to moderate kidney dysfunction is unknown.

METHODS

We tested associations of proteins in the pentraxin family [PTX3, C-reactive protein (CRP) and serum amyloid protein (SAP)] with estimated glomerular filtration rate by cystatin C (eGFRcys) and microalbuminuria among 2824 participants in the Multi-Ethnic Study of Atherosclerosis. Associations were tested using multivariable linear regression with adjustment for demographics (age, gender, annual income), comorbidities (diabetes, hypertension, smoking, body mass index, low-density lipoprotein, high-density lipoprotein, triglycerides, ACE inhibitor and statin use) and systemic inflammation [interleukin-6 (IL-6)].

RESULTS

Among the 2824 participants, mean age was 62 years and mean eGFRcys was 94 mL/min/1.73 m(2); 25% were white, 25% Chinese, 25% African-American and 25% Hispanic. Among all participants after full adjustment, higher PTX3 was associated with lower eGFRcys independently of IL-6 (β - 3.0 mL/min/1.73 m(2) per unit increase in lnPTX3, P < 0.001). In contrast, CRP and SAP were associated with eGFRcys in demographic adjusted models, but these associations were attenuated after adjustment for comorbidities and IL-6 (lnCRP β - 0.06, P = 0.9; lnSAP β - 0.35, P = 0.7). There was a significant interaction with race/ethnicity (P < 0.001) in the association of PTX3 and eGFRcys. After adjustment for demographics, comorbidities and IL-6, this association was significant in blacks (β - 5.7 mL/min/1.73 m(2) per unit increase in lnPTX3, P = 0.002) but not in Hispanics (β - 2.4, P = 0.1), Chinese (β - 0.91, P = 0.5) or whites (β - 0.26, P = 0.9). PTX3 and CRP, but not SAP, had correlations with microalbuminuria in unadjusted models (Spearman coefficients PTX3 0.05, P = 0.005; CRP 0.07, P < 0.001; SAP 0.013, P = 0.5), but these were attenuated after full adjustment.

CONCLUSIONS

Endovascular inflammation may be an important mechanism associated with early kidney dysfunction, particularly among blacks. This mechanism appears to be independent of IL-6-regulated pathways.

Hemodialysis induces p66(shc) gene expression in nondiabetic humans: correlations with oxidative stress and systemic inflammation

OBJECTIVE

Oxidative stress and inflammation characterize hemodialysis (HD) and are associated with malnutrition, cardiovascular disease, and poor clinical outcome. p66(shc) stimulates oxidative stress and atherogenesis. The objective of the present study was to assess p66(shc) expression levels in HD and their associations with inflammatory and oxidative stress markers.

DESIGN

p66(shc) messenger ribonucleic acid (mRNA) was compared with systemic oxidative stress and inflammation markers in control subjects and patients on HD before and after a single HD session in a cross-sectional analysis.

SETTING

Outpatient hemodialysis unit.

PATIENTS

The study included stable HD patients (n = 21, men/women: 18/3) who were on HD 3 times per week for a minimum of 8 weeks; age-matched control subjects (n = 22, men/women:17/5).

MAIN OUTCOME MEASURE

mRNA levels of p66(shc), tumor necrosis factor α (TNF-α), and pentraxin 3 (PTX3), p66(shc) protein levels in white blood cells, lipid peroxidation (in the form of plasma thiobarbituric acid-reactive substance [TBARS]) and serum C-reactive protein.

RESULTS

In patients on dialysis, of the p66(shc), TNF-α, and PTX3 mRNAs, p66(shc) protein levels were higher (P < .05) than in control subjects, as well as plasma TBARS and C-reactive protein (P < .05). p66(shc) mRNA directly correlated with TBARS (r = 0.69, P = .0005) and with TNF-α mRNA (r = 0.63, P = .003). These associations were confirmed in the whole study population (TBARS: r = 0.541, P = .0003; TNF-α: r = 0.581, P < .0001), whereas in the control group only the positive association between p66(shc) and TNF-α was detected. TNF-α was directly correlated with PTX3 both in HD patients (r = 0.72, P = .0005) and in the whole study group (r = 0.678, P < .0001). The dialysis session affected neither p66(shc) and TNF-α mRNA nor p66(shc) protein expression, whereas it further increased (P = .002) PTX3 mRNA. As compared with predialysis levels, TBARS were reduced (P < .05) after dialysis. In these conditions, p66(shc) remained directly correlated with TNF-α (r = 0.901, P < .0001).

CONCLUSIONS

Increased p66(shc) gene expression correlates with TNF-α mRNA and with levels of markers of oxidative stress in HD. We suggest a novel link between HD-associated inflammation and p66(shc) gene expression contributing to systemic oxidative stress.

Soluble TWEAK and PTX3 in nondialysis CKD patients: impact on endothelial dysfunction and cardiovascular outcomes

BACKGROUND AND OBJECTIVES

Chronic kidney disease (CKD) conveys high mortality rates. Soluble TNF-like weak inducer of apoptosis (sTWEAK) and long pentraxin 3 (PTX3) are predictors of mortality in dialysis patients and determinants of endothelial dysfunction. Now, we hypothesize that both sTWEAK and PTX3 act as biomarkers of cardiovascular outcomes in nondialysis CKD patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Cross-sectional analysis in which flow-mediated dilation (FMD) and intima-media thickness (IMT) were assessed in 257 nondialysis stage 1 to 5 CKD patients (mean age, 52 ± 12 years; 130 men), together with biochemical measurements and sTWEAK and PTX3 assessments. Patients were followed for cardiovascular outcomes.

RESULTS

PTX3 and IMT increased, whereas FMD and sTWEAK decreased across CKD stages (P<0.001 for all). Both PTX3 and sTWEAK appeared as strong determinants of FMD in multivariate analysis. The univariate associations of sTWEAK and PTX3 with IMT were dependent on estimated GFR. After a median of 39 months (range, 2 to 43 months), 22 fatal and 57 nonfatal cardiovascular events occurred. In a Cox model excluding PTX3, decreasing sTWEAK concentration was associated with increased risk of cardiovascular events independently of basic confounders (age, gender, estimated GFR, C reactive protein, diabetes, and cardiovascular comorbidity) and FMD. In a model excluding sTWEAK, circulating levels of PTX3 were directly associated with cardiovascular outcomes independently of basic confounders, but this association was lost after adjustment for FMD.

CONCLUSIONS

Both PTX3 and sTWEAK levels associated with the endothelial dysfunction observed with progressive kidney failure. Additionally, both biomarkers impacted the predictability of cardiovascular outcomes.

Reciprocal contribution of pentraxin 3 and C-reactive protein to obesity and metabolic syndrome

Pentraxin 3 (PTX3) is an acute-phase protein that shares structural homology with C-reactive protein (CRP). PTX3 is produced in macrophages, endothelial cells, and adipocytes in response to inflammatory stimuli, whereas hepatocytes are the main source of CRP. Because obesity and metabolic syndrome (MetS) are considered chronic inflammatory states, PTX3 might be involved in the pathogenesis of obesity and MetS as well as CRP. Levels of CRP correlated positively with body weight, BMI, waist circumference (WC), fasting plasma glucose and interleukin (IL)-6, and negatively with high-density lipoprotein cholesterol and adiponectin in healthy males. In contrast, PTX3 correlated positively with adiponectin, and negatively with body weight, BMI, WC, and triglyceride. Plasma CRP significantly increased, whereas plasma PTX3 significantly decreased with increasing BMI. Plasma CRP and PTX3 levels were significantly higher and lower, respectively, in individuals who had more than one MetS component compared with those who had none. In conclusion, PTX3 and CRP antagonistically participate in the development of obesity or MetS.

Combined therapy with renin-angiotensin system and calcium channel blockers in type 2 diabetic hypertensive patients with proteinuria: effects on soluble TWEAK, PTX3, and flow-mediated dilation

BACKGROUND AND OBJECTIVES

Soluble TNF-like weak inducer of apoptosis (sTWEAK) and long pentraxin-3 (PTX3) concentrations have been associated with endothelial function in patients with chronic kidney disease (CKD). This study tested the hypothesis that the improvement in endothelial function after initiation of angiotensin II receptor blocker (valsartan), calcium channel blocker (amlodipine) therapy, or a combination of both is directly linked to the normalization of sTWEAK and PTX3.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

One-hundred-eight diabetic CKD stage I patients with hypertension (56% men, 46.7+/-5.3 years) were allocated to a 12-week intervention with amlodipine (10 mg/d), valsartan (160 mg/d), or their combination. Plasma levels of sTWEAK, PTX3, and flow-mediated dilation (FMD) were studied during the interventions.

RESULTS

All treatment strategies effectively increased FMD and reduced proteinuria, confirming a more prone reduction with the combined therapy. These improvements were followed by significant PTX3 reductions. Valsartan alone and in combination with amlodipine achieved significant incremental raises in sTWEAK plasma levels. More importantly, the changes observed in sTWEAK (beta=0.25, P=0.006) or PTX3 (beta=-0.24, P=0.007) plasma levels were independently associated with the improvement in ultrasonographically measured FMD.

CONCLUSIONS

This study shows that treatment with antihypertensive drugs improves FMD and normalizes proteinuria, PTX3, and sTWEAK in diabetic CKD stage I patients with hypertension. The improvement in FMD was independently associated with PTX3 and sTWEAK normalization. Two surrogate biomarkers of endothelial function are therefore identified with potential as therapeutic targets. The study was registered in clinicaltrials.gov as NCT00921570.

Biochemistry and biomarkers of inflamed patients: why look, what to assess

Specific laboratory tests and physical findings are available to the practicing clinician that should raise the suspicion of inflammation. Inflammation is related to specific clinical outcomes. Once identified, changes in clinical practice may affect the level of inflammation in individual and or groups of dialysis patients with the hope that these changes may in turn affect outcome in a positive manner. Standard clinical tests and observations associated with inflammation are hypoalbuminemia, erythropoietin resistance, decreased iron saturation accompanied by high ferritin, frailty, low serum creatinine, reduced total and LDL-cholesterol, and increased C reactive protein (CRP). Inflammation is strongly associated with loss of physical function, dyslipidemia (low LDL- and HDL-cholesterol, increased triglycerides), and anemia that is unresponsive to erythropoietin. Inflammation is associated with cardiovascular events, increased hospitalization, and death. Correctible causes of inflammation are tunneled dialysis catheters, arteriovenous grafts, catheter infection, periodontal disease, poor water quality, and dialyzer incompatibility. Obesity also is a source of cytokines but may be less amenable to treatment. Inflammation is multifactorial in dialysis patients. Some sources are recognizable and correctable, such as vascular access type, clinical infection, and water quality, and some are not. Inflammation is strongly associated with outcome.

Soluble CD14 levels, interleukin 6, and mortality among prevalent hemodialysis patients

BACKGROUND

CD14 is a pattern-recognition receptor that has a central immunomodulatory role in proinflammatory signaling in response to a variety of ligands, including endotoxin. CD14 protein is present in 2 forms: soluble (sCD14) and membrane bound. Here, we studied the implications of increased sCD14 levels in hemodialysis patients. We hypothesized that sCD14 level increase may link to cytokine activation and protein-energy wasting, predisposing to increased mortality risk.

STUDY DESIGN

Prospective observational study of prevalent hemodialysis patients.

SETTING & PARTICIPANTS

211 prevalent hemodialysis patients, median age of 65 years, with 29 months of vintage dialysis time followed up for mortality for a median of 31 months.

PREDICTORS

Tertiles of baseline circulating sCD14 levels corresponding to less than 2.84, 2.85 to 3.62, and greater than 3.63 microg/mL.

OUTCOME

The major outcome of interest was all-cause mortality.

MEASUREMENTS

sCD14 and endotoxin, together with other markers of inflammation and protein-energy wasting.

RESULTS

Median sCD14 level was 3.2 microg/mL (25th to 75th percentile, 2.7 to 3.9). sCD14 level correlated positively with C-reactive protein, interleukin 6, endotoxin, and pentraxin 3 levels and negatively with serum albumin level, muscle mass, and handgrip strength. Patients with increased sCD14 levels had lower body mass index and increased prevalence of muscle atrophy. Patients within the highest sCD14 tertile had a crude morality hazard ratio of 1.94 (95% confidence interval, 1.13 to 3.32) that persisted after adjustment for multiple confounders (hazard ratio, 3.11; 95% confidence interval, 1.49 to 6.46). In patients with persistent inflammation, the presence of a concurrent sCD14 level increase gradually increased mortality risk, but this effect was less than multiplicative and failed to show a statistical interaction.

LIMITATIONS

Those inherent to an observational study.

CONCLUSIONS

sCD14 level is associated with inflammation and protein-energy wasting in hemodialysis patients. It is a strong and independent predictor of mortality that warrants further assessment in the clinical setting regarding its usefulness as a complementary prognosticator to other general inflammatory markers.

Effect of renin angiotensin system blockade on pentraxin 3 levels in type-2 diabetic patients with proteinuria

BACKGROUND AND OBJECTIVES

Long pentraxin 3 (PTX3) is a multimeric inflammatory mediator. Increased serum PTX3 levels have been reported among end-stage renal disease patients. Moreover, PTX3 has been suggested to represent a novel mortality risk factor, and elevated PTX3 levels have been shown to accompany increased albuminuria among patients with chronic kidney disease (CKD).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We analyzed data of 49 persons with stage 1 diabetic CKD and 32 healthy subjects in a prospective controlled trial. Endothelial dysfunction was determined by flow-mediated dilation (FMD). Serum PTX3, high-sensitivity C-reactive protein (hs-CRP) levels, and FMD were studied in baseline and after 12 wk of ramipril therapy. Stepwise multivariate regression analysis evaluated the association of FMD with clinical and serologic parameters.

RESULTS

Serum PTX3, hsCRP, and albumin levels and proteinuria were significantly decreased, and FMD levels were significantly increased, after ramipril treatment. FMD was negatively correlated with serum PTX3, 24-h proteinuria, and hsCRP levels and positively correlated to serum albumin both at baseline and after the 12-wk treatment period. Multivariate regression analysis revealed that PTX3 levels were independently related to FMD both before and after ramipril treatment.

CONCLUSIONS

Our study shows that serum PTX3 levels are associated with endothelial dysfunction in patients with stage 1 diabetic CKD, independent of CRP. In addition, short-term ACE-inhibitor treatment significantly improves FMD and normalizes PTX3, hsCRP, and urinary protein excretion. (NCT: The study was registered in clinicaltrials.gov as NCT00674596.).